This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

It so happened that the schedule of this month is not replete with rounds (coordinators, we hope for you!). Therefore I decided to partially correct the situation. All the problems of this round were invented and prepared by me on the last day of Hello Muscat Programming Bootcamp 2019 and on flights from Muscat to St. Petersburg. I even specially noted the time for preparation: for the current moment (the problems are ready for testing) I spent about 6 hours on their preparation, including inventing some of the problems. I really like working on problems, this is something at the intersection of creativity and programming. I really hope you enjoy the result of my work.

I am in Oman while writing the problems for the round.

The round will be hosted by rules of educational rounds (extended ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over. You will be given 6-8 problems for 2 hours to solve them.

Note that the penalty for incorrect submissions in this round is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participants of the third division, you must:

take part in at least two rated rounds (and solve at least one problem in each of them),

do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

We supported the rendering of LaTeX-formulas with MathJax in new posts and comments. Now the formulas will be as beautiful as in problem statements. Drawback: they are displayed not immediately, but redrawn after the page is displayed. Old posts and comments are displayed in the old way (already a lot of old content, backward compatibility is very important). Note that if you edit old post, it will still be displayed in the old style.

I`m glad to invite everybody to the #546 Codeforces round, which will be held on Monday, March 11, 2019 at 19:35. The round will be rated for all participants from the second division (with rating below than 2100). As usually, we will be glad to see participants from the first division out of competition!

Right now happens the first tour of the Open Olympiad in Informatics, and tomorrow will be the second one. This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Team Olympiad, Moscow Olympiad for Young Students and Metropolises Olympiad (rounds 327, 342, 345, 376, 401, 433, 441, 466, 469, 507, 516, 541)

Open Olympiad consists of the most interesting and hard problems that are proposed my a wide community of authors, so we decided to conduct a Codeforces regular round based on it, which will happen Mar/08/2019 12:05 (Moscow time) and will be based on both days of the Olympiad. Each division will have 6 problems and 2:30 hours to solve them.

We kindly ask all the community members that are going to participate in the competition to show sportsmanship by not trying to cheat in any manner, in particular, by trying to figure out problem statements from the onsite participants. If you end up knowing some of the problems of Moscow Open Olympiad (by participating in it, from some of the onsite contestants or in any other way), please do not participate in the round. We also ask onsite contestants to not discuss problems in public. Failure to comply with any of the rules above may result in a disqualification.

Hello! Codeforces Round #544 (Div. 3) will start at Mar/07/2019 18:05 (Moscow time). You will be offered 6 or 7 problems (or 8) with expected difficulties to compose an interesting competition for participants with ratings up to 1600. Probably, participants from the first division will not be at all interested by this problems. And for 1600-1899 the problems will be too easy. However, all of you who wish to take part and have rating 1600 or higher, can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.

You will be given 6 or 7 (or 8) problems and 2 hours to solve them.

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participants of the third division, you must:

take part in at least two rated rounds (and solve at least one problem in each of them),

do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

Thanks to MikeMirzayanov for the platform, help with ideas for problems and for coordination of my work. Thanks to my good friends Mikhail PikMike Piklyaev, Maksim Ne0n25 Mescheryakov and Ivan BledDest Androsov for help in round preparation and testing the round.

Good luck!

I also would like to say that participants who will submit wrong solutions on purpose and hack them afterwards (example) will not be shown in the hacking leaders table.

This round is organised in collaboration with Hello Muscat Programming Bootcamp and supported by Sberbank, General Partner of the boot camp and one of the largest banking leaders of Eastern Europe, providing thousands of jobs and innovation in the financial industry.

As the Hello Muscat Programming Bootcamp’s General Partner, Sberbank made it possible for students from some of the world’s top universities to attend the bootcamp, by sponsoring their participation. This includes students from Saint-Petersburg State University, Moscow Institute of Physics and Technology (MIPT), Penza State University, National Research Mordovia State University; MRSU, ITMO, Higher School of Economics / Moscow, Volgograd State Technical University, Lobachevsky State University of Nizhni Novgorod, Moscow Aviation Institute, Tyumen industrial University, University of Haifa, Northern (Arctic) Federal University, Saratov State University, Ural Federal University.

Hello Muscat Bootcamp will take place from 9th to 15th of March, and 120 students from 24 universities, including MIPT, Saint Petersburg State University and University of Tokyo will compete and practice side-by-side, smoothing the road towards the April World Finals in Porto.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

For those who want to compete on the same problems, we will hold two regular Codeforces Rounds in the evening: one for the first division, and another one for the second. The rounds are starting at Mar/03/2019 18:35 (Moscow time)!

If you are a participant of the official Technocup Finals, you are not allowed to take part in the rounds at evening. We ask participants of the official Finals not to discuss the problems in open media till evening.

Good luck!

The rounds are over. We sincerely apologize for the fail with the mirror rounds, we thought the editorial was only streamed to other sites of the olympiad, not online. You can read MikeMirzayanov's comment about the situation. I hope you enjoyed solving the problems even though they did not affected your rating.